trihalomethane (THMs) water Articles
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Formation potential of trihalomethanes (THMs) in blended water treated with chlorine
This study was conducted in the laboratory to assess the formation potential of trihalomethanes (THMs) in blended water under various treatment conditions. Three batches of water samples prepared by mixing desalinated (product) water and ground brackish water with three different proportions (i.e. 1:2, 1:5 and 1:10 – brackish:product water) were treated with three concentration levels of calcium ...
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Trihalomethane reduction in drinkable water by controlled chlorination and use of hydrogen peroxide
The reduction of trihalomethane (THM) formation in the water treatment process by a controlled chlorination of ammonia and successive quenching with hydrogen peroxide has been studied. The optimum values of the process parameters have been determined with a calculation programme that makes use of the kinetic constants determined with the water to be treated. The obtained data have been verified ...
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Method for trihalomethane analysis in drinking water by solid-phase microextraction with gas chromatography and mass spectrometry detection
Headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry detection (HS/SPME-GC/MSD) was optimized for trihalomethane (THM) determination in drinking water. A 75 μm fiber coated with carboxen/polydimethylsiloxane (75-CAR.PDMS) was used. Experimental parameters such as sample volume, time and temperature of extraction, time and temperature of desorption, ...
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THM Removal in Potable Water Storage Tanks - Case Study
City tests various trihalomethane removal systems to ensure full EPA compliance. Topics: trihalomethane, THM, TTHM, spray aeration, potable water tanks, GridBee® SN Series THM Removal System Project Overview: This location had a tank battery of four similar 1.5 MG bolted steel tanks installed serving as temporary storage during the planning & construction of two 6 MG pre-stressed ...
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Study of the effect of pipe materials and mixing phenomenon on trihalomethanes formation and diffusion in a laboratory-scale water distribution network
The objective of this study was to evaluate the factors that affect the formation and diffusion of disinfection by-products, especially trihalomethanes (THM), in a laboratory-scale water distribution network constructed with three different pipe materials. Sampling locations were chosen on the basis of residence time, pipe material and mixing zone. Water samples were collected and analyzed ...
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Tank Mixing & Spray Aeration Helps Stop "Flushing For DBP / THM Compliance"
Disinfection By-Products (DBPs) can be very difficult to remove in certain areas of a water system especially dead-end & low demand areas where water can sit for an extended period of time. In the case of trihalomethanes (THMs), the longer water sits, the more THM formation potential there is. Many systems have had no other alternative but to flush out the old water and replace with more ...
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Health effects of disinfection by-products in Australian drinking waters
The disinfection of drinking water has greatly diminished the occurrence of diseases known to be caused by water-borne pathogens, but technological advances subsequent to the initial discovery of chloroform in 1974 have enabled the identification of a plethora of Disinfection By-Products (DBPs), particularly trihalomethanes (THMs), that may have injurious health effects on humans. DBPs are widely ...
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Evaluation of chitosan as a natural coagulant for drinking water treatment
Chitosan, a natural biopolymer, was evaluated for its ability to be used as a coagulant to treat water for potable use both in isolation and in combination with other water treatment technologies, specifically ion-exchange and activated carbon. Chitosan was found to be very effective for particle removal at doses far below those required for equivalent turbidity removal by inorganic coagulants. ...
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Control of disinfection byproduct (DBP) precursors by soil aquifer treatment (SAT): what length of hydraulic retention time (HRT) is necessary?
The study attempted to determine the hydraulic retention time (HRT) required for soil aquifer treatment (SAT) to reclaim water as potable water in an aspect of controlling disinfection byproduct (DBP) precursors. In order to evaluate the removal of DBP precursors, the uniform formation condition was used to estimate the formations of trihalomethanes (THMs) and haloacetic acids (HAAs). ...
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Effect of blending ratio on the formation of bromoform and bromate in blended water samples disinfected with chlorine or ozone
This study was carried out to assess the potential formation of bromoform and bromate in drinking water samples prepared by blending desalinated and brackish ground water when disinfected by chlorination or ozonation methods. The levels of bromoform and bromate were determined under various treatment conditions including blending ratios, disinfectant dosage, temperature, and reaction time. ...
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New Treatment Technology Targets TOC/DOC Removal at Florida Utility
Turn on any tap in Palm Springs, FL, and you will get crystal clear water. It has no odor, no metallic taste and compares favorably with most bottled waters. The residents are, quite naturally, very happy with it. Getting clean, refreshing water in Palm Springs was not an easy task. The ground water supply in South Florida typically contains large amounts of total organic carbon (TOC) in the ...
By Ixom
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Water residence time in a distribution system and its impact on disinfectant residuals and trihalomethanes
The most critical water quality conditions are generally found at a water distribution network's extremities, given their high residence times. As chlorine injected at the water treatment plant (WTP) or at rechlorination sites has more time to react, residual chlorine concentrations at the extremities may not be enough to prevent microbial regrowth. This study focuses on the relationships between ...
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Monitoring of chlorination disinfection by-products and their associated health risks in drinking water of Pakistan
This study reports the baseline data of chlorination disinfection by-products such as trihalomethanes (THMs) and their associated health risks in the water distribution network of Islamabad and Rawalpindi, Pakistan. THM monitoring was carried out at 30 different sampling sites across the twin cities for 6 months. The average concentration of total trihalomethanes (TTHMs) and chloroform ranged ...
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Potable tank reservoirs 6, 8, & 15 - Case study
Topics: potable, THM removal, TTHM, stratification/water age, short-circuiting, chlorine Overview: The water treatment system includes three potable water storage reservoirs (Reservoirs 6, 8 and 15) where chlorine boosting occurs before water is distributed to the community. Reservoir 6 is a 3.5 MG concrete storage tank with a height of 30 feet, a diameter of 143 feet, and a maximum daily flow ...
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Providing clean water to impoverished homes
With high mortality rates from inadequate water sanitation in developing countries, the promise of inexpensive and effective water purification methods holds end¬less opportunities to improve public health and living standards. For more than a billion people forced to use con¬taminated water, diseases such as chol¬era, typhoid, chronic dysentery and rotavirus diarrhea are constant ...
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Relationships between trihalomethanes, haloacetic acids, and haloacetonitriles formed by the chlorination of raw, treated, and fractionated surface waters
This study examined effects of coagulation and fractionation of natural organic matter on the distribution of trihalomethanes (THM), haloacetic acids (HAA), and haloacetonitriles (HAN) formed in chlorinated water. The precursors of HAA and THM were determined to be associated primarily with the hydrophobic fraction although the hydrophilic fraction is important as well. On the other hand, the ...
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Santa Cruz Meets THM/DBP Challenge with Unique Air Stripping Process - Case Study
Summary Santa Cruz has successfully demonstrated an innovative way for the City to meet its water quality goals while using process recycled water as part of its supply source. Using the recycled water had caused concern about reliably meeting the U.S. EPA THM/DBP potable water quality standards in its finished water. The City evaluated various aeration treatment processes and chose an E-Z ...
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Potable tank mixing & THM removal - Case study
Topics: potable, THM reduction, TTHM, stratification/water age, chloramine Overview: This tank is a multi-leg, torus-bottom tank with a capacity of 300,000 gallons. Overall tank height is 84 ft.; the wet riser height is 49 ft. and the height of the bowl is 35 ft. The maximum fill rate is 560 GPM, and typical inflow is estimated at 300,000 GPD. The water source for the treatment plant is a ...
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Factors affecting trihalomethane formation and speciation during chlorination of reclaimed water
A hybrid process with membrane bioreactor (MBR) and powdered activated carbon (PAC), PAC/MBR, was used for real municipal wastewater treatment and reuse. The roles of chlorine dose, contact time, pH and bromide in trihalomethane (THM) formation and speciation during chlorination of the reclaimed water were investigated. Total trihalomethane (TTHM) yield exponentially increased to maximum with ...
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Catalytic Carbons Help Remove Chloramine
Untitled Document Summary: Where chlorine creates high levels of trihalomethanes (THMs), chloramine can be an alternative for disinfecting drinking water. Removing it at the point of use (POU), however, can be more difficult than removing chlorine. When your job requires chloramine removal, you may consider using catalytic activated carbons. To view ...
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